1. Technical Field
The present disclosure relates to an electrostatic discharge (ESD) protection circuit for eliminating static electricity and an electronic device using the same.
2. Description of Related Art
ESD is a well-known phenomenon, which causes damage to electronic devices such as liquid crystal displays (LCDs) and televisions, for example. To avoid damaging a circuit by ESD, an ESD protection circuit is required.
Referring to FIG. 4, one such ESD protection circuit 1 used for LCDs includes a first diode 10, a second diode 12, and a capacitor 14. Each diode includes an anode and a cathode. The first diode 10 and the second diode 12 connect in series, and the capacitor 14 connects in parallel with the first diode 10 and the second diode 12. The anode of the first diode 10 electrically connects to ground 3; the cathode of the first diode 10 electrically connects to the anode of the second diode 12. The cathode of the second diode 12 electrically connects to a power terminal 2. A power voltage VCC inputs to the ESD protection circuit 1 through the power terminal 2.
Usually, the first diode 10 and the second diode 12 are reverse biased. If a negative electrostatic voltage inputs to the ESD protection circuit 1 through a line 16, the first diode 10 is forward biased, the voltage of the wire 16 goes to ground. If a positive electrostatic voltage, which is greater than the power voltage VCC inputs to the ESD protection circuit 1 through the wire 16, the second diode 12 is forward biased; the voltage of the wire 16 goes to the power voltage VCC. The capacitor 14 filters the positive electrostatic voltage.
However, if the absolute value of the electrostatic voltage is too great, the first diode 10, and the second diode 12 burn out easily, so the ESD protection circuit 1 cannot work normally.
What is needed is to provide an ESD protection circuit and an electric device using the same that can overcome the above-described deficiencies.